Access properties of a Windows Form which was created in another Windows Form

Question

I have created a Windows Form which emerges as pop up, and it represents MessageBox with input field (as there is not something like this already existing in C#). Now, I want to forbid this form closing if the input field is left empty. For that scenario, I am adding FormClosing event:

        private void AdditionalForm(TransferClass transfer)
        {
            Form newForm = new Form()
            {
                Width = 570,
                Height = 230,
                FormBorderStyle = FormBorderStyle.FixedToolWindow,
                ForeColor = Color.WhiteSmoke,
                Font = new Font("Century Gothic", 10, FontStyle.Bold),
                Text = "New form",
                StartPosition = FormStartPosition.CenterScreen
            };
            Label lblNew = new Label() { Left = 20, Top = 20, AutoSize = true, BackColor = Color.Transparent, ForeColor = Color.Firebrick, Font = new Font("Century Gothic", 12), Text = "SOME TEXT" };
            TextBox txtNew = new TextBox() { Left = 20, Top = 100, Width = 500, BackColor = Color.Firebrick, ForeColor = Color.WhiteSmoke, Font = new Font("Century Gothic", 12) };
            Button btnNew = new Button() { Text = "CLICK ME", Left = 20, Width = 500, Height = 50, Top = 140, DialogResult = DialogResult.OK, BackColor = Color.Firebrick, ForeColor = Color.WhiteSmoke, Font = new Font("Century Gothic", 12), FlatStyle = FlatStyle.Flat };
            btnNew.Click += (sender, e) => { newForm.Close(); };
            newForm.Controls.Add(txtNew);
            newForm.Controls.Add(btnNew);
            newForm.Controls.Add(lblNew);
            newForm.AcceptButton = btnNew;

            newForm.FormClosing += NewForm_FormClosing;

            if (newForm.ShowDialog() == DialogResult.OK)
            {
               //some function
            }
        }

        private void NewForm_FormClosing(object sender, FormClosingEventArgs e)
        {
           MessageBox.Show("Input field not be empty!", "ERROR", MessageBoxButtons.OK);
           e.Cancel = false;
        }

And this works fine if user clicks X button on a form, or ALT + F4 on a keyboard, event is going to be triggered and won't let him close the form. But if clicks on a button, the message is going to be shown also, no matter input field is empty or not, and the form is going to be closed also.

First, I wan't to prevent message from showing if btnNew was clicked and txtNew is not empty, and I can do that if I cast sender in event to button and check the name of a button. But the problem is that I don't know how can I access txtNew from FormClosing event to check if it is empty or not?

take a look at [this](https://stackoverflow.com/a/56289011/4977870) and [this](https://stackoverflow.com/q/42483348/4977870) — Anas Alweish, May 26 '19 at 12:57
e.Cancel = true is required to prevent the dialog from closing. One problem with btnNew is that it sets the DialogResult unconditionally to OK, that causes the dialog to try to close and fires the FormClosing event. Twice, its Click event handler also tries to close it. It is not obvious what it is supposed to do. Do favor an "OK" button for a dialog. The main form can decide what to do next, like showing the dialog again when you expose a "Repeat" property. Whose value you can set to true with btnNew. The problem with txtNew is that it is local variable, move it out of the method. — Hans Passant, May 26 '19 at 13:01
in your case, you should create a new public property of `TextBox` in the outside instead of creating it in the scope of `AdditionalForm`. let me know if you mean something else — Anas Alweish, May 26 '19 at 13:03
@AnasAlweish Nothing else, that will solve my problem. I was just thinking that I can access it from `FormClosing` event even it's local variable, becausse the event was connected to that form. Obviously I can't do that. — niksrb, May 26 '19 at 13:05
Thanks guys, if it is duplicate, I am going to remove it. But you helped me — niksrb, May 26 '19 at 13:06

Access properties of a Windows Form which was created in another Windows Form

0 Answers0